I had the CDU open with the expanded MAIN underneath. When I hit SHIFT 2 to go back to the full main panel, it was in a frozen state. I popped off the CDU and popped up the expanded main and all instruments were OK there. Closed it and the main full panel was still in a frozen state with the backup none-glass ATI tumbled, frozen airspeed, altitude, VSI, VOR pointers, etc. on the PFD. Eventually in clicking around it recovered. The sim was not paused during this period.737NG-800 Aerosoft package with CD service pack.

Sounds like a video card driver problem. I had that happen quite a bit with an old set of drivers. Changed drivers, and haven't had a problem since.